not give/budge/move an inch
US /nɑt ɡɪv/bʌdʒ/muːv ən ɪntʃ/
UK /nɑt ɡɪv/bʌdʒ/muːv ən ɪntʃ/

1.
to refuse to change your opinion or decision, or to refuse to be persuaded to do something
:
•
He would not give an inch on the terms of the contract.
•
Despite all the pressure, she wouldn't budge an inch from her original stance.